IVMS (LAN) System

OUTLINE
The LAN system consists of a BCM (Body Control Module) and eleven LCU's (Local Control Units). Some switches and electrical loads are connected to each LCU. Some electrical systems are directly connected to the BCM. Control of each LCU. (which is provided by a switch and electrical load), is accomplished by the BCM, via two data lines connected between the two.

Body Control Module System Description:

BCM (Body Control Module)
The BCM is a master unit of the LAN (Local Area Network), consists of microprocessor, memory and communication LSI sections and has communication and control functions. It receives data signals from the LCUs and sends electrical load data signals to them.
The BCM is described as a "control assembly (for LAN)" in the Parts Catalog.

Local Control Unit Description:

LCU (Local Control Unit)
The LCU's, which is a slave unit of the BCM, have only a communication function. It consist of communication LSI and input-output interface circuits. It receives data signals from the BCM. It controls the ON/OFF operations of electrical loads and the sleep operation. Also, it sends switch signal to the BCM.

LCU No. Table:

LCU No. Table

Control System:

Control System
System controlled in LAN system is as in the image.

Sleep Control:

SLEEP CONTROL
Sleep control prevents unnecessary power consumption. When BCM detects the above Condition, the communication between the BCM and all LCU's is stopped. Then, it is set in sleep mode after about 30 seconds.

Wake-Up Control:

WAKE-UP CONTROL
BCM releases the sleep mode of all LCUs and returns to normal control mode in the following conditions:
1. When BCM detects on ON signal from switches (shown below) which are directly connected to BCM.
2. When BCM detects a wake-up signal from the data line to LCUs.
When BCM detects a key switch OFF signal, it also returns to normal control mode.

Wake-Up Switch
^ Key switch
^ Ignition switch (ACC)
^ Headlamp switch (1st)
^ Illumination control switch
^ Door switch
^ Steering switch (TILT) (UP/DOWN)
^ Steering switch (Telescopic) (FRONT/DOWN)
^ Hood switch
^ Trunk lid unlock switch
^ Trunk Lid key cylinder tamper switch
^ Trunk room lamp switch.

Fail-Safe System Description (Part 1 Of 2):

Fail-Safe System Description (Part 2 Of 2):

Fail-Safe System
Fail-safe system operates when the computing function of the BCM is judged to be malfunctioning. If BCM sends no signal or an abnormal signal to an LCU 15 times in succession, the LCU is set in a fail-safe condition. During the fail-safe condition, operation of each electrical load is as indicated in the image.